The present invention relates to connectors used to retentively terminate conduits to an electrical junction box and, more particularly, to connectors providing dual diameter end stops.
In both commercial and residential construction, electrical conductors which run between various locations are typically housed in an outer protective jacket. Such structures are referred to as electrical conduits. One such conduit is a flexible, metallic conduit where the conduit includes an outer helically convoluted metal jacket for enhanced flexibility. The conduit is terminated to an electrical junction or outlet box and the individual conductors are terminated to an electrical device supported in the junction box.
In order to suitably retain the conduit in the junction box, a conduit connector or fitting is employed to terminate the conduit and to mechanically and electrically secure the conduit to the junction box itself. Conduit connectors of this type are well-known in the electrical connection art. These connectors typically include a cylindrical body which supports therein an end extent of the conduit. The cylindrical body is attachable to the junction box through a knockout opening to allow passage of the conductors into the junction box. A screw may be interposed through the wall of the connector body to engage the conduit thereby securely retaining the conduit within such connector body.
As mentioned, the connector is mechanically secured to the junction box. One end of the connector is positioned such that it extends through the knockout opening in the junction box and terminates within the junction box. In one application, the end extending into the junction box is threaded for receipt of a securing nut which is installed from the inside of the junction box, thus mechanically securing the connector to the box. In another application, examples of which are disclosed in U.S. Pat. Nos. 3,147,776 and 3,556,566, the cylindrical body of the connector is formed in a split-shell arrangement, whereupon tightening of the screw against the conduit causes the respective shells of the connector body to expand outwards thereby engaging the walls of the junction box about the opening.
As will be appreciated by those skilled in the art, the end extent of conduit is fully inserted within the connector prior to securing the conduit to the connector via a screw or saddle. The electrical conductors carried within the conduit thereby pass through the knockout opening end into the junction box for access by the installer. However, to prevent the conduit itself from being advanced beyond the conductor regressing end of the connector (and thereby through the knockout opening into the junction box), connectors are provided with what is commonly referred as an "end stop." The end stop reduces the diameter of the aperture extending through the conductor egressing end of the connector to a diameter less than the outer diameter of the conduit extending within the connector. In this fashion, the end extent of conduit may be inserted into the connector from the conduit receiving end, but is prevented from being advanced through the aperture of the conductor egressing end of such connector.
As will be further appreciated by those skilled in the art, the requirement to provide an end stop at the conductor egressing end of the connector has in the past required the production and marketing of distinct connectors for distinctly sized conduits. This requirement requires a manufacturer to produce various connector models, and requires the installer to purchase and have accessible such models.
Thus, there is a need in the art for a single conduit connector which is capable of providing more than a single end stop diameter, and which may therefore be used with more than a single type of conduit.